----- Original Message -----
From: "Jimmy Hess" <mysidia@gmail.com>
On Mon, Nov 21, 2011 at 3:35 PM, Mark Radabaugh <mark@amplex.net> wrote:
On 11/21/11 10:32 AM, Jay Ashworth wrote: education / resource issue. The existing methods that have been used for years with reasonable success in the IT industry can 'fix' this problem.
Careful with the attribution; you're quoting Mark, not me.
The weakness of typical IT security is probably OK, when the only danger of compromise is that an intruder might get some sensitive information, or IT might need to go to the tapes.
That just won't do, when the result of compromise is, industrial equipment is forced outside of safe parameters, resulting in deaths, or a city's water supply is shut down, resulting in deaths.
(72 character hard wrap... please.)
Hard perimeter and mushy interior with OS updates just to address known issues, and malware scanners to "try and catch" things just won't do.
Precisely. THe case in point example these days is traffic light controllers. I know from traffic light controllers; when I was a kid, that was my dad's beat for the City of Boston. Being a geeky kid, I drilled the guys in the signal shop, the few times I got to go there (Saturdays, and such). The old design for traffic signal controllers was that the relays that drove each signal/group were electrically interlocked: the relay that made N/S able to engage it's greens *got its power from* the relay that made E/W red; if there wasn't a red there, you *couldn't* make the other direction green. These days, I'm not sure that's still true: I can *see* the signal change propagate across a row of 5 LED signals from one end to the other. Since I don't think the speed of electricity is slow enough to do that (it's probably on the order of 5ms light to light), I have to assume that it's processor delay as the processor runs a display list to turn on output transistors that drive the LED light heads. That implies to me that it is *physically* possible to get opposing greens (which we refer to, in technical terms as "traffic fatalities") out of the controller box... in exactly the same way that it didn't used to be. That's unsettling enough that I'm going to go hunt down a signal mechanic and ask. Cheers, -- jra -- Jay R. Ashworth Baylink jra@baylink.com Designer The Things I Think RFC 2100 Ashworth & Associates http://baylink.pitas.com 2000 Land Rover DII St Petersburg FL USA http://photo.imageinc.us +1 727 647 1274